The present invention relates in general to a strip-feeder assembly, and more particularly, to an adjustable cam indexing feed apparatus which integrally combines forward and lateral indexing of a continuous strip from a supply thereof in a zigzag manner and in ynchronization with the operation of a strip processing machine, such as a blanking or punching machine and the like, and which apparatus incorporates an adjustable cam mechanism to effect a predetermined amount of lateral indexing while providing intermittent dwell periods during which the strip processing machine performs its intended operation upon the zigzagging strip at staggered locations therealong.
In many industries, strip material provided in continuous strip form, such as metal and plastic strips, are cut into a number of pieces of various shapes by blanking or punch presses arranged at one or more strip processing stations. In the field of metal working, such working is called blanking, and the pieces cut out or blanked from the metal strips are called blanks. As a result of increasing material costs, there has been sought techniques to reduce material waste resulting from conventional single row in-line blanking. One such technique, which has been effective to decrease material waste and therefore stimulating savings through reduced material consumption, has been the use of a double row angular blanking pattern. The angular blanking pattern is arranged in such a manner, usually a thirty degree angle between blank centers, that a more effective use of material is achieved over the previously used single row in-line blanking. In order to economize on the use of an angular blanking pattern, it is required that the strip material be advanced through the blanking operation in a forward and lateral indexing manner to effect strip feeding along a zigzag path.
One known strip-feeder assembly which advances a strip along such a zigzag path, to accommodate an angular blanking pattern, employs forward and lateral strip indexing assemblies. Forward indexing is achieved by advancing the strip by means of a pair of nip rollers intermittently operated by means of a suitable drive assembly. On the other hand, lateral indexing is achieved by a rotating cam eccentrically mounted between a pair of spaced-apart cam followers which shuttle back and forth in unison upon alternate engagement with the rotating cam. This strip-feeder assembly, however, is economical primarily when dedicated to a single blanking operation employing strips having identical angular blanking patterns. When a strip having a different angular blanking pattern is employed, it becomes necessary that the strip feeder assembly be partially disassembled, so that the eccentrically mounted cam can be substituted for one having a different eccentricity in order to accommodate a different angular blanking pattern. This, of necessity, requires disruption of the strip processing operation, as well as the intended labor costs involved in partially dissassembling and re-assembling the strip-feeder assembly.
A known strip-feeder assembly which provides for adjustably controlling the amount of lateral indexing employs a cam driven slide which reciprocates a roll feed through a crank arm and tie rod arrangement, e.g., an adjustable linkage mechanism. A screw adjustment on the crank arm and tie rod provides control of the amount of lateral indexing of the roll feed to accommodate different angular blanking patterns, i.e., different blank diameters. The adjustable linkage mechanism is often unsatisfactory in that it will not maintain its accuracy over long periods of use, as well as being difficult to repair and service because of its complex arrangement and the large number of its component parts. Other arrangements of strip-feeding assemblies are known from U.S. Pat. Nos. 4,506,574, 3,880,034, 3,248,978, 1,053,694, 4,144,783, 3,336,826, 3,785,231 and 3,668,959. To the extent that these known assemblies have recognized the aforementioned problems and have devised other arrangements for providing adjustability for lateral indexing a strip, such other arrangements have generally employed hydraulic cylinders, rotatable screw drives and the like, which result in relatively complex and expensive arrangements, additional problems or expense in synchronizing with the strip processing operations, inability to maintain accuracy, and increased maintenance of the assemblies along with its attendant increased costs.
Accordingly, it can be appreciated that there is an unsolved need for an adjustable cam indexing feed apparatus which is operative for directly influencing or controlling the amount of lateral indexing, i.e., lateral offsetting movement, without the employment of adjustable linkage systems, and which utilizes a minimum number of components, which is of a relatively simple design, which maintains its accuracy during use, and which is easily maintained for providing the desired motions and control.